U.S. patent number 6,291,770 [Application Number 09/312,567] was granted by the patent office on 2001-09-18 for wiring system and method therefor.
This patent grant is currently assigned to Leoni Wiring Systems, Inc.. Invention is credited to Paul G. Casperson.
United States Patent |
6,291,770 |
Casperson |
September 18, 2001 |
Wiring system and method therefor
Abstract
A wiring harness for use in a networked wiring system wherein
one or more multiplexed electronic circuits are contained within
the wiring harness. Provision of such electronics within the wiring
harness reduces the number of wires used in a networked wiring
system without requiring their provision within sensor or actuator
devices, or in external electronic boxes. Inclusion of such
electronics within the wiring harness also eliminates the need for
extra interconnections, and provides protection of the electronics
from environmental conditions.
Inventors: |
Casperson; Paul G. (Columbus,
IN) |
Assignee: |
Leoni Wiring Systems, Inc.
(Tucson, AZ)
|
Family
ID: |
23212063 |
Appl.
No.: |
09/312,567 |
Filed: |
May 14, 1999 |
Current U.S.
Class: |
174/72A; 174/520;
174/139; 361/826; 439/76.2; 361/827 |
Current CPC
Class: |
B60R
16/0315 (20130101); B60R 16/0207 (20130101); H02G
3/00 (20130101) |
Current International
Class: |
B60R
16/02 (20060101); H02G 3/00 (20060101); H02G
003/00 () |
Field of
Search: |
;174/72A,139,149B,154,52.2 ;361/826,827,828 ;439/76.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0 288 752 B1 |
|
Jul 1991 |
|
EP |
|
543469 A1 |
|
May 1993 |
|
EP |
|
WO 96/38322 |
|
Dec 1996 |
|
WO |
|
Primary Examiner: Reichard; Dean A.
Assistant Examiner: Walkenhorst; W. David
Attorney, Agent or Firm: Snell & Wilmer
Claims
What is claimed is:
1. A wiring harness for interconnecting, via a plurality of wires,
an electronic control unit, a plurality of electronic devices
controlled by said control unit, and a plurality of smart nodes
connected therebetween, said wiring harness comprising:
said plurality of smart nodes;
said plurality of wires; and
an overmold surrounding each one of said smart nodes and at least a
portion of said wires to thereby integrate said wires and said
smart nodes into said wiring harness.
2. The wiring harness as in claim 1 wherein said electronic devices
are sensor devices.
3. The wiring harness as in claim 1 wherein said electronic devices
are actuator devices.
4. The wiring harness as in claim 1 wherein said electronic devices
are sensor and actuator devices.
5. The wiring harness as in claim 1 wherein said overmold comprises
a flexible synthetic material.
6. The wiring harness as in claim 5 wherein said flexible synthetic
material is foamed polyurethane.
7. The wiring harness as in claim 5 further comprising stiffener
plates within said overmold.
8. The wiring harness as in claim 1, further comprising a thermally
conductive material extending from inside said overmold to the
exterior of said overmold.
9. The wiring harness as in claim 1, wherein said wires are
electrically connected to said smart node by means of insulation
displacement contacts.
10. The wiring harness as in claim 1, wherein said plurality of
wires are electrically connected to said smart node along an
unbroken length of each of said wires.
11. A wiring system comprising:
a plurality of wires;
an electronic circuit electrically connected to said wires, wherein
said electronic circuit includes a demultiplexer for processing
data multiplexed by an electronic control unit also electrically
connected to said wires;
at least one electronic device also electrically connected to said
wires; and
an overmold surrounding said wires and said electronic circuit and
a length of each of said wires in proximity to said circuit to form
an integrated wiring harness.
12. The wiring system as in claim 11 wherein said overmold
comprises a flexible synthetic material.
13. The wiring system as in claim 12 wherein said flexible
synthetic material is foamed polyurethane.
14. The wiring system as in claim 11 further comprising stiffener
plates within said overmold.
15. The wiring system as in claim 11, further comprising a
thermally conductive material extending from a position adjacent to
said electronic circuit to the exterior of said overmold.
16. The wiring system as in claim 11, wherein said wires are
electrically connected to said electronic circuit by means of
insulation displacement contacts.
17. The wiring system as in claim 11, wherein said wires are
electrically connected to said electronic circuit along an
unsevered length of each of said wires.
18. The wiring system as in claim 11, wherein said electronic
circuit is electrically connected to said electronic control unit
by no more than four of said wires.
19. A method of integrating an electronic circuit into a wiring
harness connected to a plurality of devices controlled by an
electronic control unit comprising the steps of:
connecting a plurality of wires in said wiring harness to said
electronic circuit, wherein said wires are unbroken along an area
of contact with said electronic circuit; and
encapsulating said electronic circuit within said wiring
harness.
20. The method according to claim 19 wherein said wiring harness is
composed of flexible synthetic material.
21. The method according to claim 20 wherein said flexible
synthetic material is foamed polyurethane.
22. The method according to claim 19 further comprising the step of
encapsulating stiffener plates within said wiring harness.
23. The method according to claim 19, further comprising the step
of encapsulating a thermally conductive material extending from
within said wiring harness to a point outside of said wiring
harness.
24. The method according to claim 19 wherein said wires are
electrically connected to said electronic circuit by means of
insulation displacement contacts.
25. A wiring system for an automobile comprising:
a plurality of electronic circuits;
a plurality of wires interconnecting said electronic circuits, and
one of a plurality of overmolds surrounding each one of said
electronic circuits, and surrounding a length of each of said wires
in the region proximate to said electronic circuits.
26. The wiring system according to claim 25, wherein said
electronic circuits include at least a first smart node, a second
smart node, and a third smart node, each disposed with insulation
displacement contacts;
wherein said wires interconnecting said first, second, and third
smart nodes are unsevered between said first, second, and third
smart nodes, being connected by said insulation displacement
contacts; and
wherein said first, second, and third smart nodes include circuitry
for processing multiplexed data.
27. The wiring system according to claim 26, wherein said overmolds
comprise foamed polyurethane.
28. A wiring harness for an automotive vehicle comprising:
an electronic node;
a plurality of wires; and
an overmold surrounding said electronic node and covering at least
a portion of said plurality of wires.
29. The wiring harness according to claim 28 wherein said overmold
comprises foamed polyurethane.
30. A wiring harness for interconnecting an electronic device with
a component of an operational electrical system which are
interactive with the electronic device, said wiring harness
comprising,
(a) a data link cable and a connection cable, each having one end
connected with said electronic device, and each having a portion
extending away from said electronic device and configured for
connection with a component of an operational electrical system,
and
(b) an encapsulation encompassing (i) said electronic device, (ii)
the connections between said electronic device with each of said
data link and connection cables and (iii) predetermined amounts of
each of the portions of said data link and connection cables
extending away from the electronic device.
31. An electrical system portion forming part of an operational
electrical system for a vehicle, comprising first and second
electronic devices and a wiring harness associated with said first
and second electronic devices and forming part of the operational
electrical system, said wiring harness comprising,
(a) a first data link cable and a first connection cable, each of
which is connected with a respective portion of said first
electronic device and each of which has a respective portion
extending away from said first electronic device,
(b) a second data link cable and a second connection cable, each of
which is connected with a respective portion of said second
electronic device and each of which has a respective portion
extending away from said second electronic device, and
(c) an encapsulation associated with each of said first and second
devices, the encapsulation associated with a respective electronic
device encompassing (i) the respective electronic device, (ii) the
connections between the respective electronic device with each of
the data link and connection cables associated with the respective
electronic device and (iii) predetermined amounts of each of the
portions of the data link and connection cables extending away from
the respective electronic device;
wherein said first data link cable is configured for circuit
communication with a vehicle electronic control unit, and said
second data link cable is in circuit communication with each of
said first and second electronic devices.
32. A method of forming an electronic circuit component for use in
an operational electrical system of a vehicle, comprising the steps
of (a) providing an electronic device which includes an assembly of
electronic components and which is configured to provide a function
in an operational electrical system of a vehicle, (b) providing a
wiring harness connected to said electronic device and having a
portion extending away from said electronic device and configured
for connecting the electronic device to another component of an
operational electrical system of a vehicle, and (c) encapsulating
said electronic device, the connection between said wiring harness
and said electronic device, and a selected portion of the wiring
harness which extends away from said electronic device and is
configured for connecting the electronic device to another
component of an operational electrical system of a vehicle.
Description
FIELD OF THE INVENTION
The present invention relates generally to the field of electrical
control systems. More specifically, the present invention relates
to the field of wiring harnesses for use in electrical control
systems in motor vehicles, aircraft, and industrial plants and
facilities.
BACKGROUND OF THE INVENTION
Electrical systems for automobiles are becoming increasingly
complex. Whereas the first automobiles had only simple lighting
systems, today's vehicles can have well over a mile of wires
connecting a myriad of devices to numerous microprocessors or
electronic control units (ECU's). Thus, the electrical/electronic
content of a modern automobile can exceed one third of the cost of
the vehicle.
One reason for this proliferation of wires is that, traditionally,
optional electronic functions are simply added onto a vehicle's
basic electrical system. Thus, with each added function, additional
wires are incorporated into the automobile. According to common
current practice, each device typically has 2 or more dedicated
wires connecting it to the ECU in charge of its functioning.
Therefore, with the large number of electrically controlled devices
found in modem automobiles, current ECU's have hundreds of wires
connected to them. Each added wire brings the expense of the wire
itself, and the expenses associated with the accompanying
interconnections. A solution to this proliferation of wires is
required.
As the volume of wires in automobiles increased, manufacturers
began to rely on wiring harnesses in order to create manageable
units for use in the manufacturing process. The earliest wiring
harnesses were produced by bundling wires together with tape.
Later, manufacturers began producing wiring harnesses made of
molded semi-rigid or rigid corrugated plastic conduit or woven
threading in order to protect the wiring from impact and other
environmental conditions. Metal conduits have also been used as an
alternative to hard plastics. Such harnesses are still in use
today.
More recently, it has become possible to produce wiring harnesses
out of synthetic materials which can be made soft or flexible in
particular regions so as to aid in fitting the harness into the
application, reduce vibrational noise, or to suit other such
purposes. Such wiring harnesses are described in EPO Patent No. 0
288 752 B1.
One of the suggested solutions to the proliferation of wires has
been the use of "smart" technology in the individual devices
controlled by, or sending information to, the ECU. The use of smart
technology in a device involves providing the device with the
circuitry necessary to communicate with the ECU, and interpret and
implement the commands provided by the ECU, and providing an ECU
with suitable network capabilities, such as the multiplexing of
device commands. By providing the device with a de-multiplexer, and
using device-unique identifier information, commands may be
multiplexed and sent from the ECU to various devices on the same
cable, commonly known as a data link cable, with each device
ignoring commands directed to other devices. Thus, the same data
link cable can be used to serve multiple devices, and the amount of
wiring required can be greatly reduced.
However, the incorporation of smart circuitry into each device is
expensive. Smart circuitry typically consists of an analog/digital
converter, a microprocessor, memory, a transceiver, a timing
mechanism, often provided on a printed circuit board. These
components and the boards themselves are expensive, particularly
when the cost is multiplied over the number of devices which may be
present in a modern automobile. For devices not already available
in the market with smart circuitry, standard devices must be
retooled and repackaged with smart circuitry, making this solution
even less viable. Finally, in the case of engine systems, many
devices are located in areas which are environmentally too severe
to package electronics due to heat, vibration, and the presence of
moisture.
Another suggested solution has been to provide smart electronics at
points along the wiring system external to the wiring harnesses to
handle the multiplexing functionality. This solution typically
comprises providing electronic boxes spliced into the data link
cable or involve incorporating smart electronics into already
existing connectors. These additional boxes or connectors must be
separately manufactured and incorporated into the wiring system,
resulting in additional costs, interconnections, and failure
points.
SUMMARY OF THE INVENTION
The present invention is carried out in one form by provision of a
networked wiring system wherein one or more multiplexed electronic
circuits are contained within one or more wiring harnesses. Thus,
the wiring harnesses in the control system each contain the
circuitry to effect communication between the ECU and various
devices in a vehicle over a data link cable. Under conditions
without great fluctuations in temperature, rigid plastic or metal
conduit may be used to construct the overmold of the wiring
harness. Under more extreme conditions, overmolds made of flexible
synthetic materials such as foamed polyurethane allow for normal
expansion and contraction without damaging the internal circuitry,
and can be made watertight, so as to prevent damage caused by
moisture.
The present invention provides a solution to the proliferation of
wires in modern electrical control systems without the expense of
incorporating circuitry into individual devices, adding discrete
electronic boxes, or increasing the number of connector interfaces.
Thus, the cost of materials is reduced, and manufacturing time and
costs are saved. The present invention can be implemented without
redesigning, replacing, or retooling existing devices.
An additional advantage provided by the present invention is the
protection of sensitive circuitry from environmental stressors such
as heat, cold, vibration, shock, moisture, and impact.
The present invention may be advantageously implemented into any
electrical system, including those in motor vehicles, aircraft,
industrial plants and facilities, where the cost and performance
advantages of fabricating electronic circuits directly into a
wiring assembly can by achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in conjunction
with the appended drawing Figures, wherein like numerals designate
like elements, and:
FIG. 1 is a top view of a control system in accordance with one
embodiment of the present invention;
FIG. 2 is a top view of a smart node in accordance with another
embodiment of the present invention;
FIG. 3 is a side view of the smart node of FIG. 2;
FIG. 3B is a close-up front view of an insulation displacement
contact as in FIG. 3;
FIG. 4 is a top view of a control system in accordance with the
prior art.
FIG. 5 is a top view of a control system in accordance with another
embodiment of the present invention.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
First with reference to FIG. 4, a control system 400 according to
the prior art is shown. According to the prior art control system
400, smart electronics are provided inside electronic boxes 404,
which are typically constructed of rigid metals or plastics.
Communication between ECU 402 and electronic boxes 404 is conducted
across ECU connector 401, a section of data link cable 408a, a
first connector 410, and a second connector 412, which is connected
to an electronic box 404. In order for messages to continue to
other electronic boxes 404, the first electronic box 404 is
connected to a third connector 414, which interfaces to a fourth
connector 416, which is spliced to a second section of data link
cable 408b. This same series of connector interfaces repeats for
each additional electronic box 404 in prior art control system 400.
Additionally, signals relayed from electronic boxes 404 to devices
414 over connection cables 412 must cross multiple interfaces, such
as across connectors 420 and 422. At each such splice or interface,
the strength of electronic signal may be diminished. Further
disadvantages associated with the costs of providing electronic
boxes 404 and coupling them into control system 400 with connectors
410, 412, 414, 416420, 422, are also present in this form of the
prior art.
Referring now to FIG. 1, an electrical control system 100 in
accordance with the present invention is depicted. Electronic
Control Unit (ECU) 102 is connected to wiring harness 105 by data
link cable 104 and ECU connector 101. Wiring harness 105 consists
of one or more "smart nodes" 103, which are each connected to one
or more devices 108, such as actuator and sensor devices, by
connection cables 106 and connectors 107. As will be described in
greater detail below, these smart nodes 103 are comprised primarily
of electronic circuits which allow the smart nodes 103 to process
signals, and to act as "mini-ECU's" in electrical control system
100, thus forming a control system in which ECU 102 is primarily
responsible for the functioning of devices 108, while the smart
nodes 103 function to buffer commands and data between ECU 102 and
devices 108. Wiring harness 105 preferentially has mounting
fixtures 109 for suitable attachment of wiring harness 105 to a
frame or other structure.
Signals from ECU 102 travel along data link cable 104 to the smart
nodes 103. Each smart node 103 interprets these signals to
determine whether activation of a device 108 connected to it is
required. Similarly, signals from devices 108 travel along
connection cables 106 to the smart nodes 103, and each smart node
103 interprets these signals to determine whether the information
should be forwarded to ECU 102. In this way, the devices 108 are
each in communication with ECU 102 over a single data link cable
104, a smart node 103, and a branching connection cable 106.
Devices 108 may be continuously sending or receiving information to
or from ECU 102, or may send or receive information upon the
occurrence of a given condition. Any suitable protocol for
communications between the ECU 102 and the smart nodes 103 may be
used. Examples of such protocols include SAE J1708/1587, SAE J1939,
CAN, and high speed CAN.
Now with reference to FIG. 2, a close-up of a smart node 202 is
shown. Smart node 202 comprises printed circuit board 212 with
suitable electronic circuitry 214 disposed thereon, overmold 208,
and data link cable 104 and connection cables 106 suitably
connected to printed circuit board 212. Overmold 208 serves as the
exterior casing of smart node 202, and may be constructed of a
variety of materials, including rigid plastics or metals. In the
preferred embodiment of the present invention, overmold 208 is
constructed of a flexible synthetic material, such as foamed
polyurethane or other flexible polymeric material. Foamed
polyurethane provides the benefits a high level of environmental
protection, and ease of manufacture, while not damaging solder
connections, as do many prior art potting compounds. Overmold 208
fully encases smart node 202, and portions of data link cable 104
and connection cables 106.
In a typical application, such as a wiring system for an
automobile, electronic circuitry 214 usually includes at least a
microprocessor, a multiplexer/demultiplexer, a transceiver, and a
synchronization clock, for use in processing higher level logic
functions, such as interpreting and communicating multiplexed
digital format information transmitted over data link cable 104 to
or from ECU 102 (FIG. 1). Electronic circuitry 214 may also
comprise electronics to measure conditions and convert the data to
a signal, to enhance signals, convert signals, or to make
corrections such as by controlling temperature or other devices.
Such electronics are commonly referred to in the relevant art as
"smart electronics." Provision will usually be made on smart node
202 for connection to power input and output, ground input and
output, datalink high input and output, datalink low input and
output, sensor power and actuator power, sensor ground and actuator
ground, sensor signal, and sensor signal ground wires, such as data
link wires 210 and connection wires 220, discussed in greater
detail below.
In the event that the smart electronic circuitry 214 is used in
connection with one or more actuator devices, such as lamps,
heaters, solenoids, fuel injectors, pumps, and various other motors
and engine components, suitable "driver" circuitry is included for
causing activation of the actuator devices. Common sensor devices
include devices such as thermistors, thermocouples, pressure
sensors, fluid level switches, and various other engine
sensors.
It will be understood that the particular electronic circuitry 214
for an application will vary with the application, and that various
functions may be integrated into the same components. Further,
printed circuit board 212 may comprise a rigid board, or may be
made of one of the flexible materials now known in the art.
Alternatively, printed circuit board 212 may be eliminated
altogether, with the electronic circuitry being packaged directly
within overmold 208, or by other suitable means.
With continuing reference to FIG. 2, connection cables 106 further
comprise sets of connection wires 220, and, optionally, connection
cable jackets 218. With additional reference to FIG. 3, data link
cable 104 is comprised of a set of data link wires 210 running in
unbroken contact across the bottom of printed circuit board 102,
and, optionally, data link cable jacket 216.
Data link wires 210 are depicted as four individual wires,
representing power, ground, data link high, and data link low. It
will be appreciated, however, that the precise number of data link
wires 210 utilized will vary per the application chosen. Thus, two,
three, four, five, or more data link wires 210 may comprise the
data link cable 104. Additionally, more than one data link cable
104 may be used, depending on the application.
Still with reference to FIG. 2, connection wires 220 are depicted
as sets of two or three wires. Connection wires 220 for connection
of smart node 202 to sensor devices commonly comprise power,
ground, signal, and signal ground wires, though many sensors
commonize the power and signal wires, and the ground and signal
ground wires, thus necessitating only two or three wires.
Connection wires 220 for connection of smart node 202 to actuator
devices commonly comprise power and ground wires. It is possible to
not use a ground return through the wiring harness. Thus, only one
or two connection wires 220 may be necessary for an actuator
device. Thus, it will be appreciated that the number of connection
wires 220 will also vary suitably with a given application of the
present invention.
With reference to FIG. 3, uninterrupted contact between smart node
202 and ECU 102 (FIG. 1) may be achieved by the use of insulation
displacement contacts 310, as are well known, though not previously
used within a wiring harness for direct connection to a printed
circuit board. FIG. 3B shows one insulation displacement contact
310 in contact with one data link wire 210. Insulation displacement
contact 310 makes electrical contact with the electrically
conductive strands 312 which comprise data link wire 210 by
piercing the jacket of data link wire 210. Preferably, insulation
displacement contact 310 may be provided with a protective plastic
housing (not shown). Examples of suitable insulation displacement
contacts include AMP-BARREL Terminals.
With continued reference to FIG. 3, insulation displacement
contacts provide for electrical connection of the data link wires
210 to the printed circuit board 212 without the use of traditional
wiring interconnects, which involve a wire to a first connector
terminal crimp, a first connector terminal to a second connector
terminal interface, a second connector terminal to a wire crimp,
and then a solder joint to a printed circuit board. Such
interconnects can be expensive, and can interrupt the flow of
signals over data link cable 104. Optionally, connection wires 220
are also connected to printed circuit board 212 by insulation
displacement contacts, though any of the wiring connections to
printed circuit board 212 may be made by commonly known methods
such as soldering, resistance welding, or ultrasonic welding.
Further, any of the disclosed connection methods may also be used
in an application of the present invention wherein the electronic
circuit is not disposed on a printed circuit board.
Still with reference to FIG. 3, in the event that all or part of
overmold 208 is formed of flexible material, stiffener plates 314
composed of any suitable material may be provided within the wiring
harness to provide increased protection of the printed circuit
board 212 or electronics 214 from strong impact, penetration, or
harmful flexure.
With reference now to FIG. 2, regardless of the composition of
overmold 208, in a further preferred embodiment of the present
invention, as is known in the art, a heat conductor 222, composed
of a thermally conductive material such as copper or aluminum may
be attached to printed circuit board 212 in close proximity with
heat generating components within smart node 202, such as the
electronic circuitry comprising the smart nodes, and extend to a
point external to overmold 208. Optionally, this material can be
attached to a metallic frame or housing to further facilitate heat
transfer. Thus, means for removing heat from smart node 202 is
provided, while providing a means for securing and supporting smart
node 202.
As is well known, the flow of electricity over wires such as data
link wires 210 and connection wires 220 will create electromagnetic
fields which may potentially interfere with other nearby electrical
functions. Likewise, electromagnetic fields created by other
sources may interfere with the signals transmitted over data link
wires 210 and connection wires 220. Optionally, cable shields (not
shown) may be provided around smart node 202, data link cable 104
and connection cables 106 to block such interference.
With reference to FIG. 5, an alternative embodiment of the present
invention is depicted. Control system 500 comprises wiring harness
502, connected to ECU 504 and electronic devices 506. Wiring
harness 502 comprises a single electronic node 508, containing an
electronic circuit (not shown) for processing and relaying signals
from electronic devices 506 to ECU 504 over wires 505 contained in
wiring harness 502. Electronic node 508 is encased in polyurethane
overmold 510, which also substantially extends over the length of
wires 505. Wires 505 are in electrical contact with ECU connector
512 and device connectors 514, which mate in electrical contact
with ECU 504 and electronic devices 506, respectively. Signals from
electronic devices 506 travel to electronic node 508, which
processes and/or relays signals to ECU 504. Polyurethane overmold
510 replaces and provides greater protection of wires 505 than
traditional cable jackets. Wiring harness 502 may be provided with
an identification tag 516.
It will be appreciated that the present invention may be
implemented in various applications and ways other than the
embodiments discussed above. While the principles of the invention
have now been made clear in illustrative embodiments, there will be
immediately obvious to those skilled in the art many modifications
of structure, arrangements, proportions, elements, materials, and
components used in the practice of the inventions which are
particularly adapted for a specific environment and operating
requirements without departing from those principles, or the scope
of the invention, as set forth in the appended claims. For example
various combinations of sensor devices and actuator devices may be
connected to a given smart node. Further, the particular
electronics, the number and combination of ECU's, wiring harnesses,
and smart nodes, and the form of the overmolds may be varied in
accordance with the requirements of a particular application.
* * * * *